JP2005292742A - Plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma display device in which an electric field and a magnetic field from a panel body are reduced. <P>SOLUTION: In the plasma display panel for color display which is constituted of arranging an optical filter on the front side of a front glass plate, the optical filter is provided with an electric field/magnetic field absorption layer for absorbing visible light in a fixed range in order to improve contrast and absorbing an unnecessary electric field and an unnecessary magnetic field which are caused on the plasma display panel for color display, and the electric field/magnetic field absorption layer is constituted of a metallic mesh having ferromagnetism. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to unnecessary radiation of a plasma display device known as a thin, lightweight display device having a large screen.

  In recent years, plasma display devices have attracted attention as display panels (thin display devices) with excellent visibility, and higher definition and larger screens are being promoted.

This plasma display device is roughly classified into an AC type and a DC type in terms of driving, and there are two types of discharge types: a surface discharge type and a counter discharge type. Therefore, at present, AC-type and surface-discharge-type plasma display devices are mainly used.
First, the structure of the plasma display panel in the plasma display device will be described with reference to FIG. 4 shows a cross section taken along line AA ′ in FIG. 3, and FIG. 5 shows a cross section taken along line BB ′ in FIG. As shown in the figure, a plurality of pairs of striped display electrodes 4 which are paired with a scanning electrode 2 and a sustaining electrode 3 are formed on a transparent front substrate 1 such as a glass substrate. A light shielding layer 5 is disposed between adjacent display electrodes 4. The scan electrode 2 and the sustain electrode 3 are respectively composed of transparent electrodes 2a and 3a and buses 2b and 3b made of silver or the like electrically connected to the transparent electrodes 2a and 3a. A dielectric layer 6 is formed on the front substrate 1 so as to cover the plurality of pairs of electrodes, and a protective film 7 is formed on the dielectric layer 6.

  Further, an insulating layer 9 is covered on the rear substrate 8 facing the front substrate 1 in a direction perpendicular to the scanning electrodes 2 and the display electrodes 4 of the sustain electrodes 3 on the substrate 1. A plurality of stripe-shaped data electrodes 10 are formed. On the insulator layer 9 between the data electrodes 10, a plurality of stripe-shaped partition walls 11 are arranged in parallel with the data electrode 10, and the phosphor layer 12 is formed on the side surface 11 a between the partition walls 11 and the surface of the insulator layer 9. Is provided.

  The substrate 1 and the substrate 8 are arranged to face each other with a minute discharge space so that the scan electrode 2 and the sustain electrode 3 and the data electrode 10 are orthogonal to each other, and the periphery is sealed, and the discharge In the space, for example, one kind or a mixed gas of helium, neon, argon, xenon, or the like is sealed as a discharge gas. In addition, the discharge space is divided into a plurality of sections by partition walls 11 to provide a plurality of discharge cells 13 at which the intersections of the display electrodes 4 and the data electrodes 10 are located. The phosphor layers 12 are sequentially arranged one by one so as to be blue.

  Next, the operation of the panel body will be described. The electrode arrangement of the panel body has a matrix configuration composed of M × N discharge cells (M and N are integers) as shown in FIG. M rows of scan electrodes SCN1 to SCNM and sustain electrodes SUS1 to SUSM are arranged in the direction, and N columns of data electrodes D1 to DN are arranged in the column direction.

  FIG. 7 shows an example of a timing chart of a driving method of an AC type plasma display device using this panel body.

  As shown in FIGS. 6 and 7, in the write period, after all the sustain electrodes SUS1 to SUSM are held at 0 volts (V), predetermined data electrodes D1 to D1 corresponding to the discharge cells to be displayed in the first row are displayed. When a positive write pulse voltage + Vw (V) is applied to DN and a negative scan pulse voltage -Vs (V) is applied to the scan electrode SCN1 in the first row, the predetermined data electrodes D1 to DN and the first row are applied. Write discharge occurs at the intersection with the scan electrode SCN1.

  Next, positive write pulse voltage + Vw (V) is applied to predetermined data electrodes D1 to DN corresponding to discharge cells to be displayed in the second row, and negative scan pulse voltage -Vs is applied to scan electrode SCN2 in the second row. When (V) is applied to each, an address discharge occurs at the intersection of predetermined data electrodes D1 to DN and scan electrode SCN2 in the second row.

  The same operation as described above is sequentially performed. Finally, a positive write pulse voltage + Vw (V) is applied to predetermined data electrodes D1 to DN corresponding to discharge cells to be displayed in the Mth row, and the Mth row is scanned. When a negative scan pulse voltage −Vs (V) is applied to each electrode SCNM, an address discharge occurs at the intersection of predetermined data electrodes D1 to DN and the Mth scan electrode SCNM.

  In the next sustain period, all the scan electrodes SCN1 to SCNM are temporarily held at 0 (V), and when a negative sustain pulse voltage −Vm (V) is applied to all the sustain electrodes SUS1 to SUSM, an address discharge is caused. In addition, a sustain discharge occurs between scan electrodes SCN1 to SCNM and sustain electrodes SUS1 to SUSM at the intersections. Next, by applying negative sustain pulse voltage −Vm (V) alternately to all scan electrodes SCN1 to SCNM and all sustain electrodes SUS1 to SUSM, sustain discharge continuously occurs in the display discharge cells. Panel display is performed by the light emission of the sustain discharge.

  In the next erasing period, all the scan electrodes SCN1 to SCNM are temporarily held at 0 (V), and when the erasing pulse voltage −Ve (V) is applied to all the sustain electrodes SUS1 to SUSM, an erasing discharge is caused to cause a discharge. Stops.

  Through the above operation, one screen is displayed in the AC type plasma display apparatus.

  FIG. 8 shows an example of the overall configuration of a plasma display device incorporating the panel body described above. In the figure, a case for housing the panel body 14 is composed of a metal front case portion 15 and a back case portion 16, and a light transmitting portion 17 made of glass or the like is provided on the front surface of the front case portion 15. . Further, the back case portion 16 is provided with a plurality of vent holes 16a for releasing heat generated in the panel body 14 and the like to the outside.

  The panel body 14 is held by adhering it to the front surface of an aluminum chassis member 18 via an insulating heat conductive sheet 19, and on the rear surface side of the chassis member 18, the panel body 14 is driven to emit light. A plurality of circuit blocks 20 are attached. The heat conductive sheet 19 is for efficiently transmitting the heat generated in the panel body 14 to the chassis member 18 for heat dissipation, and the circuit block 20 is an electric for driving and controlling the light emission of the panel body 14. A circuit is provided, and is electrically connected to the electrode lead-out portion that is led out to the edge portion of the panel body 14 by a plurality of flexible wiring boards (not shown) extending beyond the four edge portions of the chassis member 18. Yes.

Further, on the rear surface of the chassis member 18, a plurality of radiating fins 18a, a plurality of boss portions 18b for attaching the circuit block 20, and a boss portion 18c for fixing the chassis member 18 to the back case portion 16 are die-cast. Or projecting by integral molding such as casting.
(For example, refer to Patent Document 1).

In the plasma display device having the above-described configuration, a current of about 400 mAp-p flows through one set of the scan electrode and the sustain electrode in the sustain period, and therefore, when there are M rows of electrodes, 0.4 Ap-p × M = 0. 4M Ap-p
For example, if M is 480, a discharge current of 192 Ap-p flows. Therefore, electromagnetic interference caused by a current of about 192 Ap-p is an important issue.

  Furthermore, electromagnetic waves are known to cause damage to instruments, and recently it has been reported that electromagnetic waves may also damage the human body. For this reason, the electromagnetic wave emission is in a legally regulated direction. For example, in Japan, there is a regulation by VCCI (Voluntary Control Council for Interference by data processing equipment electronic machinery machine), and in the United States by FCC (Federal Communications). Regarding electromagnetic interference as described above, electromagnetic wave shielding filters are widely used for televisions and computer CRT monitors as electromagnetic wave shielding applications.

  For example, in Patent Document 2, the plasma display panel (PDP) requires a low-resistance and transparent electromagnetic wave blocking filter in order to block the electromagnetic wave having the intensity that emits strong electromagnetic waves from the display portion to the outside due to its light emission principle. It is stated that.

  In the above-mentioned Patent Document 2, in developing a low resistance transparent conductive thin film, it is effective to use a metal thin film layer, particularly a metal thin film layer using silver having the smallest specific resistance among pure substances, and further increase the transmittance. For the purpose of improving the stability of the metal thin film layer, it is very effective to form a transparent conductive thin film laminate by sandwiching the metal thin film layer with a transparent high refractive index thin film layer. It has been proposed that by selecting the material and film thickness of each thin film layer, it can be designed to have optimum optical characteristics and electrical characteristics according to the application.

  Further, in Patent Document 2, silver, which is suitably used because of its low specific resistance as a metal thin film layer material, has a surface that tends to cause aggregation of atoms. For example, aggregation easily occurs in the presence of chloride ions or in an electric field. Aggregation of silver atoms in the silver thin film produces a silver white point, losing the inherent high transparency and low resistance. One method for suppressing the aggregation of silver is to alloy silver. Common metals used for alloying are gold, copper, and palladium. Conventionally, an alloy composed of silver, palladium, and copper has been the most durable silver alloy material. In particular, when a silver alloy containing 1 weight percent of palladium and copper is used, the durability of the transparent conductive thin film laminate is not significantly impaired as compared with the case of using pure silver without significantly degrading high transparency and low resistance. Can be improved.

However, these transparent conductive thin film laminates tend to cause aggregation of silver atoms in the silver thin film layer in the presence of chloride ions or by passing an electric current. Therefore, it is also stated that when used as a transparent electrode or an electromagnetic wave shielding filter member, point defects due to silver aggregation were likely to occur.
Japanese Patent Laid-Open No. 10-240138 JP 2003-225964 A

  In the conventional configuration, it has been a problem to reduce the electromagnetic wave emitted from the panel body with a metal body having a low conductivity. However, as described above, a peak alternation of about 200 Ap-p is generated inside the panel of the plasma display device. Since current always flows, there is a need to separate and reduce electromagnetic waves rather than simply reducing electromagnetic waves. In order to further reduce electromagnetic waves, an electromagnetic wave filter using copper or silver has been introduced to the front glass, but copper and silver are non-magnetic materials, so it becomes a shield with sufficient effect for unnecessary electric field components, As for the magnetic field, when an alternating magnetic field crosses a copper or silver nonmagnetic metal, only an external high frequency magnetic field canceling effect due to an eddy current generated inside the copper or silver nonmagnetic metal can be expected. Reduction of the generated magnetic field unnecessary radiation component has been an issue.

  An object of the present invention is to solve such problems and to reduce an electric field and a magnetic field from a panel body.

  In order to achieve the above object, a plasma display device according to the present invention is a color display plasma display panel in which an optical filter is provided on the front side of a front glass plate. And an unnecessary electric field generated in the plasma display panel for color display and an electric field / magnetic field absorbing layer that absorbs an unnecessary magnetic field are made of a metal mesh having ferromagnetism.

  With this configuration, a metal mesh having ferromagnetism is used, so electric field absorption as well as eddy current external magnetic field cancellation effect in nonmagnetic materials are inferior to nonmagnetic metals (having nonmagnetic properties such as copper and silver) However, it is possible to absorb unnecessary radiant electric fields and particularly unnecessary radiant magnetic fields generated in the plasma display panel for color display due to the magnetic field shielding effect of the metal body having ferromagnetism.

  In the plasma display device of the present invention, a filter formed of a metal mesh having ferromagnetism in an electric field / magnetic field absorption layer that absorbs an unnecessary electric field and an unnecessary magnetic field generated in the color display plasma display panel is provided inside the back cover. With this configuration, it is possible to absorb unnecessary radiation electric field and particularly unwanted radiation magnetic field generated in the plasma display panel for color display, and to achieve a special effect for countermeasures against unwanted radiation.

  According to the plasma display device of the present invention, since a ferromagnetic metal is used as a filter, it is possible to reduce unnecessary electric field components by the inherent low resistance of the metal, and for unnecessary magnetic field components, metal Therefore, unnecessary radiation of electric and magnetic fields to the periphery of the plasma display device can be reduced.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view of a front electric field / magnetic field filter 25 with an optical filter for plasma display according to Embodiment 1 of the present invention. In the exploded perspective view of the entire configuration of the plasma display device (FIG. 8), the front electric field / magnetic field filter 25 with an optical filter is attached to the plasma panel side on the surface of the light transmitting portion 17.

  As described above, a series of driving operations of the plasma display device is realized by flowing current through a plurality of electrodes constituting the plasma display panel in order to display one screen.

  Here, in this plasma display device, a ferromagnetic metal mesh is applied to the electric field / magnetic field filter 17 with an optical filter to shield the electric field / magnetic field, and the periphery of the ferromagnetic metal mesh is grounded. The electric field / magnetic field is prevented from being emitted from the front side of the plasma display panel.

  In FIG. 1, a front electric field / magnetic field filter optical filter 25 with an optical filter is formed by forming a metal mesh 22 having ferromagnetism on the panel body 14 side of an optical filter (or protective sheet) 21 and further protecting (contacting) the metal mesh 22. A sheet 23 is formed. Moreover, the protective sheet 23 is not formed in the peripheral part of the metal mesh 22 which has ferromagnetism, but it has the structure which takes earth | ground by the connection part 26 of FIG.

  Next, a method for fixing the front surface electric field / magnetic field filter 25 with the optical filter for plasma display will be described with reference to FIG. 9A is a front electric field / magnetic field filter 25 with an optical filter for plasma display as viewed from the plasma display panel 14 side, and FIG. 9B is a cross-sectional view as viewed from the side of the plasma display device.

  The protective sheet 23 in FIG. 9A is provided in contact with the ferromagnetic metal mesh 22 leaving the periphery of the ferromagnetic metal mesh 22 as described in FIG. In a region where the protective sheet 23 is not provided, a presser fitting 27 for the front electric field / magnetic field filter 25 with an optical filter is provided as a connection portion 26. The presser fitting 27 is made of metal, and one end is fixed to the front case portion 15, and the front electric field / magnetic field filter 25 with an optical filter is fixed to the other end.

  In FIG. 9, all four sides of the front electric field / magnetic field filter 25 with the optical filter are fixed by the presser fitting 27, but this is not always necessary, and only two opposing sides may be provided.

  The presser fitting 27 is electrically connected to the ferromagnetic metal mesh 22 of the front electric field / magnetic field filter 25 with an optical filter, and the ferromagnetic metal mesh 22 is grounded through the presser fitting 27.

  The metal mesh 22 is made of a ferromagnetic material such as iron, nickel, or an iron alloy, and is formed in a mesh state on the optical filter 21.

  With the above configuration, in the plasma display device of this embodiment, the front electric field / magnetic field filter optical filter 25 with an optical filter controls light such as suppressing reflection of external light and is generated from the plasma display panel. It absorbs an electric field or a magnetic field and makes it possible to suppress unnecessary electromagnetic waves radiated from the front surface of the plasma display device.

  In the plasma display device of the present embodiment, the front electric field / magnetic field filter optical filter with an optical filter has been described as an example of a configuration that prevents an electric field / magnetic field emitted from the plasma display panel. However, unnecessary radiation emitted from the plasma display panel is described. If the filter made of a ferromagnetic material is arranged on the front side of the plasma display panel, the front electric field with an optical filter described above is used for that purpose.・ Magnetic filter Equivalent effect to optical filter.

The same effect can be obtained by replacing the metal mesh 22 made of a ferromagnetic material with a filter formed by sputtering the ferromagnetic metal.
(Embodiment 2)
FIG. 2 is an explanatory diagram of the second embodiment of the present invention. In FIG. 2, the same components as those in FIG.

  In FIG. 2, a metal plating 24 having a conductivity lower than that of the metal mesh 22 is applied on (in contact with) the metal mesh 22 having ferromagnetism. Further, a protective sheet 23 is provided on (in contact with) the metal plating 24. In the protective sheet 23, for example, the metal mesh 22 is made of iron, and the metal plating 24 is made of silver.

By adopting such a configuration, the shielding effect against the electric field / magnetic field as an electric field filter is improved, and eddy currents increase on the metal plating 24 of the electric field / magnetic field filter 25 with an optical filter, so that the magnetic field cancellation is reduced. Further improvement is possible.
(Embodiment 3)
Next, a third embodiment of the present invention will be described. In (Embodiment 1) and (Embodiment 2), the configuration for mainly preventing the electric field or magnetic field radiated from the front surface of the plasma display device has been described. However, from the plasma display device, not only from the front surface but also from the rear surface. Since there are electric and magnetic fields that are radiated, a configuration example for shielding these electric and magnetic fields will be described.

  FIG. 10 is a view as seen from the side of the plasma display device. Components having the same reference numerals as those in FIG. 9B described in the first embodiment perform the same configuration and operation.

  The front electric field / magnetic field filter 25 with an optical filter is fixed to the front case 15 by a pressing metal fitting 27 around the periphery. The front electric field / magnetic field filter 25 with the optical filter is not described in detail, but it may be composed of the optical filter 21, the metal mesh 22, and the protective sheet 23 as shown in FIG. 1, or as shown in FIG. The structure which consists of the optical filter 21, the metal mesh 22, the low power transmission rate metal plating 24, and the protective sheet 23 may be sufficient.

  The plasma display panel 14 is configured by bonding a front glass substrate and a rear glass substrate, and the rear glass substrate is fixed to the chassis member 18 via a heat conductive sheet 19. The front glass substrate is provided at a position facing the front electric field / magnetic field filter 25 with an optical filter. The electric field / magnetic field radiated from the front glass substrate side of the plasma display panel 14 is mainly the front glass substrate. Absorption by the magnetic field filter 25 and emission to the outside of the plasma display device are suppressed.

  The back case portion 31 is provided connected to the front case portion 15, and the front glass substrate has the plasma display panel 14 and the chassis member 18 formed by the front electric field / magnetic field filter 25 with an optical filter, the front case portion 15, and the back case portion 31. Surrounding. Although not shown, a circuit board for driving the plasma display panel 14 is fixed to the rear surface side of the chassis member 18, and light emission control of each pixel of the plasma display panel 14 is performed by a signal from the circuit board. Has been made.

  An electric field / magnetic field filter 30 is provided on the inner surface side of the back case portion 31. The electric field / magnetic field filter 30 is made of, for example, a surface of a fiber fabric made by meshing or sputtering a ferromagnetic material such as iron, nickel, ferrite, or the like. An electric field / magnetic field filter 30 is attached to the inner surface side of the back case portion 31. The electric field / magnetic field filter 30 is electrically connected to the presser fitting 27 and is grounded.

  With the configuration of the present embodiment, it is possible to suppress the electric field / magnetic field radiated from the plasma display panel 14 from being radiated from the plasma display device. Further, as in the present embodiment, the front glass substrate can be used together with the front electric field / magnetic field filter 25 with an optical filter to suppress unnecessary radiation such as an electric field / magnetic field from the front case part 15 and the back case part 31. It may be used alone.

  In addition, the electric field / magnetic field filter 30 may not be attached to the inside of the back case portion 31, and may be provided so as to cover each circuit board fixed to the chassis member 18.

  According to the configuration of the present embodiment, the amount of the electric field emitted from the plasma display panel 14 and the electromagnetic wave due to the magnetic field are absorbed by the electric field / magnetic field filter 30 provided in the surroundings, thereby suppressing the amount of the electric field coming out from the plasma display device. Is effective. Therefore, by reducing unnecessary radiation from the plasma display device according to this embodiment, the plasma display device can be operated without adversely affecting the operation of surrounding equipment.

  In the present embodiment, the configuration of the electric field / magnetic field filter 30 is an example in which a ferromagnetic material is attached to the surface of the fiber fabric. However, the present invention is not limited to this configuration, and the electric field / magnetic field is disposed behind the plasma display panel 14. The same effect can be obtained even with a filter having a configuration similar to that of the filter 30. For example, the back case part 31 may be formed by meshing or sputtering a ferromagnetic material such as iron, nickel, or ferrite.

  Furthermore, if the back case portion 31 is made of a ferromagnetic material, the same effect as the electric field / magnetic field filter 30 can be obtained, and there is no need to provide the electric field / magnetic field filter 30. Since the back case portion 31 made of a ferromagnetic material is provided connected to the front case portion 15 and is grounded, unnecessary radiation can be reduced. In this case, since the electric field / magnetic field filter 30 is not required for the plasma display panel 14 and the back case portion 31, the space inside the plasma display device can be further narrowed.

  Since the plasma display device according to the present invention uses a metal mesh filter having ferromagnetism, the plasma display device has an excellent absorption characteristic with respect to unnecessary magnetic field absorption as well as unnecessary electric field absorption. It is very useful as a plasma display device for reducing unnecessary radiation as a display device.

Sectional drawing of the front surface electric field / magnetic field filter with an optical filter of the plasma display apparatus in one embodiment of this invention Sectional drawing of the front surface electric field and magnetic field filter with an optical filter of the plasma display apparatus in other embodiment of this invention Diagram showing the structure of a plasma display panel The figure which showed the section of the same plasma display panel The figure which showed the section of the same plasma display panel The figure which shows the electrode arrangement of the plasma display panel The figure which showed the drive method of the AC type plasma display apparatus as a signal waveform diagram The exploded perspective view which shows an example of the whole structure of a plasma display apparatus The figure which shows the structure for pressing down the front surface electric field and magnetic field filter with an optical filter of the plasma display apparatus in other embodiment of this invention. Sectional drawing of the plasma display apparatus in other embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front side substrate 2 Scan electrode 3 Sustain electrode 4 Display electrode 5 Light shielding layer 6 Dielectric layer 7 Protective film 8 Back side substrate 9 Insulator layer 10 Data electrode 11 Partition 12 Phosphor layer 13 Discharge cell 14 Panel body 15 Front Case part 16, 31 Back case part 17 Translucent part 18 Chassis member 19 Thermal conductive sheet 20 Circuit block
21 Optical filter (or protective sheet)
22 Metal mesh having ferromagnetism 23 Protective sheet 24 Low conductivity metal plating 25 Front electric field / magnetic field filter with optical filter 26 Connection part 27 Press fitting 30 Electric field / magnetic field filter

Claims (7)

A plasma display device comprising an optical filter provided on the front side of a front glass plate, wherein the optical filter is provided with an electric field / magnetic field absorption layer for absorbing an unnecessary radiation electric field and an unnecessary radiation magnetic field. apparatus. 2. The plasma display device according to claim 1, wherein the electric field / magnetic field absorption layer is formed by attaching a ferromagnetic metal body by sputtering (vapor deposition). 2. The plasma display device according to claim 1, wherein the electric field / magnetic field absorption layer is plated with a metal having a low resistivity. A plasma display device comprising a back cover portion covering a rear surface side of the plasma display panel, wherein the back cover portion is made of a ferromagnetic metal. In a plasma display device including a back cover portion covering the rear surface side of the plasma display panel, an electric field / magnetic field absorption layer for absorbing an unnecessary radiation electric field and an unnecessary radiation magnetic field is provided between the back cover portion and the plasma display panel. A plasma display device. 6. The plasma display device according to claim 5, wherein the electric field / magnetic field absorption layer is provided by being attached to the inner side surface of the back cover portion. 6. The plasma display device according to claim 5, wherein the electric field / magnetic field absorbing layer is formed by attaching a ferromagnetic metal body to the inner side surface of the back cover portion by sputtering (vapor deposition).

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